Current Nanoscience - Volume 8, Issue 1, 2012

Current Nanoscience is now entering its 8th year of publication. Over the last seven years it has established itself as a very respectable journal in its field, and has a growing Impact Factor. The journal publishes authoritative reviews, original research and highlight reports that are written by experts in the field on all the most important advances in nanoscience and nanotechnology. The fields covered include synthesis, properties, assembly and devices, applications of nanoscience in biotechnology, medicine, pharmaceuticals, physics, material science and electronics as well as nano- structures, nano-bubbles, nano-droplets, and nanofluids. The continued growth and success of Current Nanoscience are due to the enthusiasm and hard work of the Associate, Assistant and Regional Editors as well as the editorial Board Members for which I am grateful. I also wish to thanks the editorial staff of Bentham Science Publishers including Ms. Humaira Hashmi, Ms. Sidra Aftab and Mr. Ansar Ahmed for their cooperation and hard work.

Novel functional poly (ethylene terephthalate) (PET)/TiO2 nanofibers have been prepared by electrospinning the homogeneous solution of PET and titania precursor, tetra-n-butyl titanate (TBT), in trifluoroacitic acid (TFA). In situ growth of TiO2 nanoparticles in electrospun PET nanofibers has been successfully achieved via a simple hydrothermal process at low temperature. X-ray diffraction (XRD) patterns showed that the crystalline phase of TiO2 nanoparticles in PET electrospun nanofibers was anatase phase. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observation revealed that anatase TiO2 nanoparticles were uniformly dispersed both on the surface and inside of the PET nanofibers. The as-prepared PET/TiO2 nanofibers showed highly photocatalytic activity and excellent reutilization properties in photodegradation of methyl orange.

Nano-Au/C catalysts were prepared by loading the gold nanoparticles which were prepared by photochemical reduction method to the activated carbon. They were used for the catalytic oxidation reaction of glyoxal into glyoxylic acid. The influence of temperature and pH on the catalytic activity, and the mechanism of Au/C catalyst on catalytic oxidation of glyoxal were discussed. The amount ratio of Au: glyoxal is 1:1000; The pH of solution can be controlled between 8.2 to 8.4 by using 1.00 mol/L NaOH solution under 45°. Activity of the catalyst slowly decreased after 14 runs.

Melting processes of a truncated icosahedral Cu135 cluster have been studied by employing molecular dynamics method based on the embedded-atom method (EAM) potential. The detailed information of structure and energy changes has been obtained by dividing Cu135 cluster into six shell regions according to radical density distribution peaks of atoms. The simulation results show that the melting behavior of the Cu135 cluster presents new pattern, its melting behaviors show similar to the bulk, there is definitive melting point (791K). Stable and particular surface structures of Cu135 cluster, which is identical structure with C60 cluster, play important role. The simulation results also show there is bigger internal strain in the Cu135 cluster and lower surface energy at 300K, and the internal strain gets release by the volume of the Cu135 cluster expanding with temperature rising.

Gold nanoparticles(GNPs) are very suitable for the drug carrier because of their intrinsic properties. Protein- or peptide- type drugs are popular at present with their high treatments. So the research of gold nanoparticles conjunction with proteins is attractive now. In this paper, the conjunction calculated relationships between gold nanoparticles and the protein are researched. Bull Serum Albumin (BSA) and Egg White Lysozyme (EWL) and two different sizes of gold nanoparticles are checked. The condition of conjunction is determined by spectrometry, followed by calculating the binding protein quantity of the surface of a gold nanoparticle and occupied area of a single protein. The results show that the quantity of bound protein in the surface of a gold nanoparticle increases with the particle size of gold nanoparticle; while more proteins are bound by gold nanoparticles when the molecular mass of protein is smaller.

The WO3 nanorods and WO3·0.33H2O nanowires are fabricated by a hydrothermal method in the presence of NaCl and K2SO4, respectively. The products are characterized in detail by multiform techniques: X-ray diffraction (XRD), energy-dispersive X-ray analysis( EDS), scanning electron microscopy(SEM), and transmission electron microscopy(TEM). The WO3 nanorods have diameters ranging from 40-60 nm, and lengths ranging between 500-800 nm. The WO3·0.33H2O nanowires obtained have diameter of 10-15 nm, and lengths of about several microns. The effects of the preparation conditions such as the concentration and species of inorganic salts on the crystalline phase and morphology of the products have been studied systematically. The prepared WO3 nanorods and WO3·0.33H2O nanowires are used as electrode materials to study the electrochemical properties in 1 M LiClO4 solution. The WO3·0.33H2O nanowires showed higher current for lithium intercalation than the WO3 nanorods.

Silver nanoparticles offer a broad range of applications in biomedical and bioanalytical areas. In lieu of inadequate prior reports the present study aims to investigate the differential interaction of silver nanoparticles with cysteine and glutathione. Cysteine and glutathione were chosen as the model biomolecules owing to its strong affinity towards silver nanoparticles and potential applications in the field of biomedicine. Cysteine induced aggregation of particles but under similar experimental conditions glutathione failed to cause aggregation. The interaction of silver nanoparticles with cysteine resulted in a shift in the plasmon bands to higher wavelengths, which was further confirmed by microscopic studies which showed randomly arranged aggregates of the particles. The disappearance of the - SH band in the FT-IR spectra and the shift in the peaks of COO- and NH3 + groups indicated the S-Ag interaction and the aggregation of the particles. Further DLS and zeta potential measurements showed relatively high degree of polydispersity confirming the aggregation of the particles. The positive amine group of cysteine formed salt bridges with carboxylate groups which result in the aggregation of the particles. Unlike in the cysteine treated samples the FT-IR spectra of glutathione treated samples did not show any shift in the peaks of COO- and NH3 + stretching, confirming that these groups have not taken part in the interaction in order to cause the aggregation of the particles. We anticipate that further improvements on this approach will enable the exploitation of the nanoparticles functionalized with amino acids containing thiol group towards bio-sensing applications.

We report the shape transformation of ZnO nanorods/nanotubes at temperatures (∼700 °C) much lower than the bulk melting temperature (1975 °C). With increasing annealing temperature, not only does shape transformation take place but the luminescence characteristics of ZnO are also modified. It is proposed that the observed shape transformation is due to surface diffusion, contradicting the previously reported notion of melting and its link to luminescence. Luminescence in the green-to-red region is observed when excited with a blue laser, indicating the conversion of blue to white light.

The Wiener index of a molecular graph G is defined as the summation of topological distances between all pair of atoms in G. In this paper an algorithm by Sandi Klavzar [European J. Combin. 2006, 27, 68-73] is applied to calculate the Wiener index of one-heptagonal nanocone L[n]. It is proved that W(L[n]) = (238/5)n5 + (238)n4 + (2821/6)n3 + (917/2)n2 + (3311/15)n + 42.